Electronic device and wireless communication system thereof

ABSTRACT

An electronic device includes a network monitor configured to acquire network environment information related to a radio frequency (RF) transmission signal; a transceiver configured to generate an envelope signal of the RF transmission signal; a transmission (Tx) module including a power amplifier for receiving the RF transmission signal from the transceiver and amplifying the RF transmission signal; and an envelope tracking (ET) modulator configured to receive the envelope signal from the transceiver and to provide a bias of a power amplifier to correspond to the envelope signal, wherein the ET modulator determines a magnitude of the bias of the power amplifier based on the network environment information acquired by the network monitor.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119to Korean Patent Application No. 10-2019-0089599, filed on Jul. 24,2019, in the Korean Intellectual Property Office, the disclosure ofwhich is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates generally to an electronic device, and moreparticularly, to an electronic device including a radio frequency(RF)-based wireless communication system.

2. Description of Related Art

A portable electronic device may have a wireless communication functionto provide various functions to a user. A wireless communication systemincluded in the electronic device has been developed to support a higherdata rate in order to meet the ever-increasing data traffic demand.Various technologies such as envelope tracking (ET), digitalpre-distortion (DPD), or crest factor reduction (CFR) are used toimprove the overall efficiency of a wireless communication system suchas high data rate and power consumption.

In the currently developed fifth generation (5G) network environment, ahigher bandwidth than a commercialized network is used, and signals of alegacy network and a 5G network may be configured and used incombination. Accordingly, signals with a wider range of bandwidths maybe used in a 5G network environment compared to a conventional wirelesscommunication system.

Since a conventional wireless communication system does not require ahigh bandwidth, limited parameters have been used when implementing ET,DPD, or CFR. However, in the 5G network environment, higher bandwidthscenarios should be considered, and therefore it may be advantageous tointroduce parameters that are adapted to the network environment basedon power consumption and system stabilization.

SUMMARY

The present disclosure has been made to address the above-mentionedproblems and disadvantages, and to provide at least the advantagesdescribed below.

In accordance with an aspect of the disclosure, an electronic deviceincludes a network monitor configured to acquire network environmentinformation related to an RF transmission signal; a transceiverconfigured to generate an envelope signal of the RF transmission signal;a transmission (Tx) module including a power amplifier for receiving theRF transmission signal from the transceiver and amplifying the RFtransmission signal; and an ET modulator configured to receive theenvelope signal from the transceiver and to provide a bias of a poweramplifier to correspond to the envelope signal, wherein the ET modulatordetermines a magnitude of the bias of the power amplifier based on thenetwork environment information acquired by the network monitor.

In accordance with another aspect of the disclosure, a control method ofa wireless communication system of an electronic device includesacquiring network environment information related to an RF transmissionsignal; generating an envelope signal of the RF transmission signal; andproviding a bias of a power amplifier for amplifying the RF transmissionsignal to correspond to the envelope signal, wherein providing the biasincludes determining a magnitude of the bias of the power amplifierbased on the network environment information.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the present disclosure will be more apparent from thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a diagram illustrating an electronic device in a networkenvironment, according to an embodiment;

FIG. 2 is a block diagram illustrating a wireless communication system,according to an embodiment;

FIG. 3 is a block diagram illustrating an electronic device, accordingto various embodiments;

FIG. 4 is a block diagram illustrating an ET system, according to anembodiment;

FIG. 5 is a block diagram illustrating an ET modulator and a poweramplifier of a Tx module, according to an embodiment;

FIG. 6A is a block diagram illustrating an ET modulator, according to anembodiment;

FIG. 6B is a diagram illustrating current waveforms in an ET modulator,according to an embodiment;

FIG. 7 is a block diagram illustrating an ET modulator that performs ETaccording to a network environment, according to an embodiment;

FIG. 8 is a graph illustrating a bias and a pass current according to asignal bandwidth in an ET modulator that performs ET according to anetwork environment, according to an embodiment;

FIG. 9 is a diagram illustrating a structure of a linear regulator of anET modulator, according to an embodiment;

FIG. 10 is a diagram illustrating a structure of a linear regulator ofan ET modulator that performs envelope tracking according to a networkenvironment, according to an embodiment;

FIG. 11 is a block diagram illustrating a modem and a transceiver forsampling rate control, according to an embodiment;

FIG. 12A is a diagram illustrating a method of determining a samplingrate, according to an embodiment;

FIG. 12B is a diagram illustrating a method of determining a samplingrate, according to an embodiment;

FIG. 12C is a diagram illustrating a method of determining a samplingrate, according to an embodiment;

FIG. 13A is a graph illustrating a gain of a power amplifier and anenvelope trajectory of an ET system, according to an embodiment;

FIG. 13B is a diagram illustrating a method of applying DPD, accordingto an embodiment;

FIG. 14A is a diagram illustrating a method of applying DPD, accordingto an embodiment,

FIG. 14B is a diagram illustrating a method of applying DPD, accordingto an embodiment;

FIG. 15 is a block diagram illustrating a wireless communication systemthat applies DPD according to a network environment, according to anembodiment;

FIG. 16 is a diagram illustrating an example of signals clipped throughCFR, according to an embodiment;

FIG. 17 is a block diagram illustrating a wireless communication systemthat controls various parameters according to a network environment,according to an embodiment; and

FIG. 18 is a flowchart illustrating a method of operating a wirelesscommunication system, according to an embodiment.

DETAILED DESCRIPTION

Various embodiments of the disclosure provide a wireless communicationsystem which is adapted to a network environment to support highefficiency and stability, and an electronic device having the same.

According to various embodiments of the disclosure, it is possible toprovide a wireless communication system which can monitor a networkenvironment in real time and optimize its performance using parametersadapted to the network environment and an electronic device having thesame.

FIG. 1 is a block diagram illustrating an electronic device 101 in anetwork environment 100 according to various embodiments. Referring toFIG. 1, the electronic device 101 in the network environment 100 maycommunicate with an electronic device 102 via a first network 198 (e.g.,a short-range wireless communication network), or an electronic device104 or a server 108 via a second network 199 (e.g., a long-rangewireless communication network). According to an embodiment, theelectronic device 101 may communicate with the electronic device 104 viathe server 108. According to an embodiment, the electronic device 101may include a processor 120, memory 130, an input device 150, a soundoutput device 155, a display device 160, an audio module 170, a sensormodule 176, an interface 177, a haptic module 179, a camera module 180,a power management module 188, a battery 189, a communication module190, a subscriber identification module (SIM) 196, or an antenna module197. In some embodiments, at least one (e.g., the display device 160 orthe camera module 180) of the components may be omitted from theelectronic device 101, or one or more other components may be added inthe electronic device 101. In some embodiments, some of the componentsmay be implemented as single integrated circuitry. For example, thesensor module 176 (e.g., a fingerprint sensor, an iris sensor, or anilluminance sensor) may be implemented as embedded in the display device160 (e.g., a display).

The processor 120 may execute, for example, software (e.g., a program140) to control at least one other component (e.g., a hardware orsoftware component) of the electronic device 101 coupled with theprocessor 120, and may perform various data processing or computation.According to one embodiment, as at least part of the data processing orcomputation, the processor 120 may load a command or data received fromanother component (e.g., the sensor module 176 or the communicationmodule 190) in volatile memory 132, process the command or the datastored in the volatile memory 132, and store resulting data innon-volatile memory 134. According to an embodiment, the processor 120may include a main processor 121 (e.g., a central processing unit (CPU)or an application processor (AP)), and an auxiliary processor 123 (e.g.,a graphics processing unit (GPU), an image signal processor (ISP), asensor hub processor, or a communication processor (CP)) that isoperable independently from, or in conjunction with, the main processor121. Additionally or alternatively, the auxiliary processor 123 may beadapted to consume less power than the main processor 121, or to bespecific to a specified function. The auxiliary processor 123 may beimplemented as separate from, or as part of the main processor 121.

The auxiliary processor 123 may control at least some of functions orstates related to at least one component (e.g., the display device 160,the sensor module 176, or the communication module 190) among thecomponents of the electronic device 101, instead of the main processor121 while the main processor 121 is in an inactive (e.g., sleep) state,or together with the main processor 121 while the main processor 121 isin an active state (e.g., executing an application). According to anembodiment, the auxiliary processor 123 (e.g., an ISP or a CP) may beimplemented as part of another component (e.g., the camera module 180 orthe communication module 190) functionally related to the auxiliaryprocessor 123.

The memory 130 may store various data used by at least one component(e.g., the processor 120 or the sensor module 176) of the electronicdevice 101. The various data may include, for example, software (e.g.,the program 140) and input data or output data for a command relatedthereto. The memory 130 may include the volatile memory 132 or thenon-volatile memory 134.

The program 140 may be stored in the memory 130 as software, and mayinclude, for example, an operating system (OS) 142, middleware 144, oran application 146.

The input device 150 may receive a command or data to be used by othercomponent (e.g., the processor 120) of the electronic device 101, fromthe outside (e.g., a user) of the electronic device 101. The inputdevice 150 may include, for example, a microphone, a mouse, a keyboard,or a digital pen (e.g., a stylus pen).

The sound output device 155 may output sound signals to the outside ofthe electronic device 101. The sound output device 155 may include, forexample, a speaker or a receiver. The speaker may be used for generalpurposes, such as playing multimedia or playing record, and the receivermay be used for an incoming calls. According to an embodiment, thereceiver may be implemented as separate from, or as part of the speaker.

The display device 160 may visually provide information to the outside(e.g., a user) of the electronic device 101. The display device 160 mayinclude, for example, a display, a hologram device, or a projector andcontrol circuitry to control a corresponding one of the display,hologram device, and projector. According to an embodiment, the displaydevice 160 may include touch circuitry adapted to detect a touch, orsensor circuitry (e.g., a pressure sensor) adapted to measure theintensity of force incurred by the touch.

The audio module 170 may convert a sound into an electrical signal andvice versa. According to an embodiment, the audio module 170 may obtainthe sound via the input device 150, or output the sound via the soundoutput device 155 or a headphone of an external electronic device (e.g.,an electronic device 102) directly (e.g., wiredly) or wirelessly coupledwith the electronic device 101.

The sensor module 176 may detect an operational state (e.g., power ortemperature) of the electronic device 101 or an environmental state(e.g., a state of a user) external to the electronic device 101, andthen generate an electrical signal or data value corresponding to thedetected state. According to an embodiment, the sensor module 176 mayinclude, for example, a gesture sensor, a gyro sensor, an atmosphericpressure sensor, a magnetic sensor, an acceleration sensor, a gripsensor, a proximity sensor, a color sensor, an infrared (IR) sensor, abiometric sensor, a temperature sensor, a humidity sensor, or anilluminance sensor.

The interface 177 may support one or more specified protocols to be usedfor the electronic device 101 to be coupled with the external electronicdevice (e.g., the electronic device 102) directly (e.g., wiredly) orwirelessly. According to an embodiment, the interface 177 may include,for example, a high definition multimedia interface (HDMI), a universalserial bus (USB) interface, a secure digital (SD) card interface, or anaudio interface.

A connecting terminal 178 may include a connector via which theelectronic device 101 may be physically connected with the externalelectronic device (e.g., the electronic device 102). According to anembodiment, the connecting terminal 178 may include, for example, a HDMIconnector, a USB connector, a SD card connector, or an audio connector(e.g., a headphone connector).

The haptic module 179 may convert an electrical signal into a mechanicalstimulus (e.g., a vibration or a movement) or electrical stimulus whichmay be recognized by a user via his tactile sensation or kinestheticsensation. According to an embodiment, the haptic module 179 mayinclude, for example, a motor, a piezoelectric element, or an electricstimulator.

The camera module 180 may capture a still image or moving images.According to an embodiment, the camera module 180 may include one ormore lenses, image sensors, ISPs, or flashes.

The power management module 188 may manage power supplied to theelectronic device 101. According to one embodiment, the power managementmodule 188 may be implemented as at least part of, for example, a powermanagement integrated circuit (PMIC).

The battery 189 may supply power to at least one component of theelectronic device 101. According to an embodiment, the battery 189 mayinclude, for example, a primary cell which is not rechargeable, asecondary cell which is rechargeable, or a fuel cell.

The communication module 190 may support establishing a direct (e.g.,wired) communication channel or a wireless communication channel betweenthe electronic device 101 and the external electronic device (e.g., theelectronic device 102, the electronic device 104, or the server 108) andperforming communication via the established communication channel. Thecommunication module 190 may include one or more CPs that are operableindependently from the processor 120 (e.g., the AP) and supports adirect (e.g., wired) communication or a wireless communication.According to an embodiment, the communication module 190 may include awireless communication module 192 (e.g., a cellular communicationmodule, a short-range wireless communication module, or a globalnavigation satellite system (GNSS) communication module) or a wiredcommunication module 194 (e.g., a local area network (LAN) communicationmodule or a power line communication (PLC) module). A corresponding oneof these communication modules may communicate with the externalelectronic device via the first network 198 (e.g., a short-rangecommunication network, such as Bluetooth™, wireless-fidelity (Wi-Fi)direct, or infrared data association (IrDA)) or the second network 199(e.g., a long-range communication network, such as a cellular network,the Internet, or a computer network (e.g., LAN or wide area network(WAN)). These various types of communication modules may be implementedas a single component (e.g., a single chip), or may be implemented asmulti components (e.g., multi chips) separate from each other. Thewireless communication module 192 may identify and authenticate theelectronic device 101 in a communication network, such as the firstnetwork 198 or the second network 199, using subscriber information(e.g., international mobile subscriber identity (IMSI)) stored in thesubscriber identification module 196.

The antenna module 197 may transmit or receive a signal or power to orfrom the outside (e.g., the external electronic device) of theelectronic device 101. According to an embodiment, the antenna module197 may include an antenna including a radiating element composed of aconductive material or a conductive pattern formed in or on a substrate(e.g., PCB). According to an embodiment, the antenna module 197 mayinclude a plurality of antennas. In such a case, at least one antennaappropriate for a communication scheme used in the communicationnetwork, such as the first network 198 or the second network 199, may beselected, for example, by the communication module 190 (e.g., thewireless communication module 192) from the plurality of antennas. Thesignal or the power may then be transmitted or received between thecommunication module 190 and the external electronic device via theselected at least one antenna. According to an embodiment, anothercomponent (e.g., a radio frequency integrated circuit (RFIC)) other thanthe radiating element may be additionally formed as part of the antennamodule 197.

At least some of the above-described components may be coupled mutuallyand communicate signals (e.g., commands or data) therebetween via aninter-peripheral communication scheme (e.g., a bus, general purposeinput and output (GPIO), serial peripheral interface (SPI), or mobileindustry processor interface (MIPI)).

According to an embodiment, commands or data may be transmitted orreceived between the electronic device 101 and the external electronicdevice 104 via the server 108 coupled with the second network 199. Eachof the electronic devices 102 and 104 may be a device of a same type as,or a different type, from the electronic device 101. According to anembodiment, all or some of operations to be executed at the electronicdevice 101 may be executed at one or more of the external electronicdevices 102, 104, or 108. For example, if the electronic device 101should perform a function or a service automatically, or in response toa request from a user or another device, the electronic device 101,instead of, or in addition to, executing the function or the service,may request the one or more external electronic devices to perform atleast part of the function or the service. The one or more externalelectronic devices receiving the request may perform the at least partof the function or the service requested, or an additional function oran additional service related to the request, and transfer an outcome ofthe performing to the electronic device 101. The electronic device 101may provide the outcome, with or without further processing of theoutcome, as at least part of a reply to the request. To that end, acloud computing, distributed computing, or client-server computingtechnology may be used, for example.

The electronic device according to various embodiments may be one ofvarious types of electronic devices. The electronic devices may include,for example, a portable communication device (e.g., a smartphone), acomputer device, a portable multimedia device, a portable medicaldevice, a camera, a wearable device, or a home appliance. According toan embodiment of the disclosure, the electronic devices are not limitedto those described above.

It should be appreciated that various embodiments of the disclosure andthe terms used therein are not intended to limit the technologicalfeatures set forth herein to particular embodiments and include variouschanges, equivalents, or replacements for a corresponding embodiment.With regard to the description of the drawings, similar referencenumerals may be used to refer to similar or related elements. It is tobe understood that a singular form of a noun corresponding to an itemmay include one or more of the things, unless the relevant contextclearly indicates otherwise. As used herein, each of such phrases as “Aor B,” “at least one of A and B,” “at least one of A or B,” “A, B, orC,” “at least one of A, B, and C,” and “at least one of A, B, or C,” mayinclude any one of, or all possible combinations of the items enumeratedtogether in a corresponding one of the phrases. As used herein, suchterms as “1st” and “2nd,” or “first” and “second” may be used to simplydistinguish a corresponding component from another, and does not limitthe components in other aspect (e.g., importance or order). It is to beunderstood that if an element (e.g., a first element) is referred to,with or without the term “operatively” or “communicatively”, as “coupledwith,” “coupled to,” “connected with,” or “connected to” another element(e.g., a second element), it means that the element may be coupled withthe other element directly (e.g., wiredly), wirelessly, or via a thirdelement.

As used herein, the term “module” may include a unit implemented inhardware, software, or firmware, and may interchangeably be used withother terms, for example, “logic,” “logic block,” “part,” or“circuitry”. A module may be a single integral component, or a minimumunit or part thereof, adapted to perform one or more functions. Forexample, according to an embodiment, the module may be implemented in aform of an application-specific integrated circuit (ASIC).

Various embodiments as set forth herein may be implemented as software(e.g., the program 140) including one or more instructions that arestored in a storage medium (e.g., internal memory 136 or external memory138) that is readable by a machine (e.g., the electronic device 101).For example, a processor (e.g., the processor 120) of the machine (e.g.,the electronic device 101) may invoke at least one of the one or moreinstructions stored in the storage medium, and execute it, with orwithout using one or more other components under the control of theprocessor. This allows the machine to be operated to perform at leastone function according to the at least one instruction invoked. The oneor more instructions may include a code generated by a complier or acode executable by an interpreter. The machine-readable storage mediummay be provided in the form of a non-transitory storage medium. Wherein,the term “non-transitory” simply means that the storage medium is atangible device, and does not include a signal (e.g., an electromagneticwave), but this term does not differentiate between where data issemi-permanently stored in the storage medium and where the data istemporarily stored in the storage medium.

A method according to various embodiments of the disclosure may beincluded and provided in a computer program product. The computerprogram product may be traded as a product between a seller and a buyer.The computer program product may be distributed in the form of amachine-readable storage medium (e.g., compact disc read only memory(CD-ROM)), or be distributed (e.g., downloaded or uploaded) online viaan application store (e.g., PlayStore™), or between two user devices(e.g., smart phones) directly. If distributed online, at least part ofthe computer program product may be temporarily generated or at leasttemporarily stored in the machine-readable storage medium, such asmemory of the manufacturer's server, a server of the application store,or a relay server.

According to various embodiments, each component (e.g., a module or aprogram) of the above-described components may include a single entityor multiple entities. According to various embodiments, one or more ofthe above-described components may be omitted, or one or more othercomponents may be added. Alternatively or additionally, a plurality ofcomponents (e.g., modules or programs) may be integrated into a singlecomponent. In such a case, according to various embodiments, theintegrated component may still perform one or more functions of each ofthe plurality of components in the same or similar manner as they areperformed by a corresponding one of the plurality of components beforethe integration. According to various embodiments, operations performedby the module, the program, or another component may be carried outsequentially, in parallel, repeatedly, or heuristically, or one or moreof the operations may be executed in a different order or omitted, orone or more other operations may be added.

FIG. 2 is a block diagram illustrating a wireless communication system,according to an embodiment.

The wireless communication system 200 may constitute at least a portionof a wireless communication module 192 of an electronic device 101.

Referring to FIG. 2, the wireless communication system 200 includes amodem 220, a transceiver 230, a Tx module 240, and an ET modulator 250.The illustrated components may only show some components that form a Txpath in the wireless communication system 200, and various componentsnot shown may be further included. The wireless communication system 200may further include various components for processing an RF receptionsignal received from an antenna.

The wireless communication system 200 of FIG. 2 may perform ET, DPD, orCFR for an RF transmission signal, but may not include a network monitor360 that monitors network environment information.

The modem 220 may perform modulation and demodulation of signals in thewireless communication system 200. The modem 220 may use variousmodulation and demodulation schemes such as a phase shift keying (PSK)method such as binary PSK (BPSK) or quadrature PSK (QPSK), and aquadrature amplitude modulation (QAM) method such as 64-QAM or 256-QAM.Various modulation and demodulation schemes are not limited to the aboveexamples.

The modem 220 may transmit and receive in phase and in quadrature (I/Q)signals of a digital baseband to and from the transceiver 230 using eachchannel.

The transceiver 230 may perform digital/analog conversion based on thesignals transmitted from the modem 220, may up/down-convert a basebandsignal into an RF signal, and may transmit and receive an RF signal toand from an RF front end module.

Referring to FIG. 2, the transceiver 230 includes a CFR block 231, adigital to analog converter (DAC)/analog to digital converter (ADC)block 232, a Tx operator 233, an Rx operator 234, an envelope trackingdigital signal processor (ET DSP) 235, a digital pre-distortion (DPD)block 236, and an analyzer/calibration block 237.

The analyzer/calibration block 237 may check an output power of a Txsignal to adjust the Tx signal. The analyzer/calibration block 237 mayacquire information related to the output power of the Tx signal in realtime from the Tx module 240 through an FBRx path.

The CFR block 231 may perform CFR on the input/output (I/O) signal ofthe digital baseband transmitted from the modem 220 for the purpose ofcontrolling high power, high efficiency, and high linearity of a poweramplifier (PA) 241 of the Tx module 240. The CFR is a technique used toreduce a peak to average power ratio (PAPR) of the PA, and will bedescribed later in more detail through FIG. 16.

The DAC/ADC block 232 may convert a CFR processed signal into an analogsignal and may convert a reception signal received from an externaldevice through an antenna into a digital signal. In FIG. 2, the DAC/ADCis shown as one block 232, but the independent DAC block and ADC blockmay be arranged in a Tx path and an Rx path, respectively.

The Tx operator 233 may process an analog transmission signal processedby the DAC/ADC block 232 to transmit the processed analog transmissionsignal to the Tx module 240.

The Rx operator 234 may process an analog reception signal receivedthrough an antenna to transmit the processed analog reception signal tothe modem 220 through the DAC/ADC block 232.

The ET DSP 235 may generate and process an envelope signal input to theET modulator 250. For example, the ET DSP 235 may generate the envelopesignal of the RF signal, may adjust the type of the envelope signal,and/or may adjust a delay.

The DPD block may perform DPD to compensate for signal compression whenan ET technology is applied. The DPD block 236 may performpre-distortion before an I/Q signal is applied to the Tx module 240 byusing a coefficient of a stored DPD lookup table (LUT). The I/Q signalinput from the modem 220 to the transceiver 230 may be converted into adigital signal after CFR and DPD are applied. The DPD will be describedlater in more detail with reference to FIGS. 13 to 15.

In FIG. 2 and the above description, the DAC/ADC block 232, the CFRblock 231, and the DPD block 236 are described as being included in thetransceiver 230, but according to various embodiments, some of theDAC/ADC block 232, the CFR block 231, or the DPD block 236 may beincluded in the modem 220. In this case, the modem 220 may convert theI/Q signal into a digital signal after DPD and CFR processing isperformed on the I/Q signal, and may transmit the obtained digitalsignal to the transceiver 230.

The ET modulator 250 may receive the envelope signal generated from thetransmitted RF signal from the transceiver 230, and may amplify theenvelope signal to apply the amplified signal as the input power of thepower amplifier of the Tx module 240. The ET modulator 250 may include alinear regulator 251 and a switching converter 252. The linear regulator251 may linearly amplify the envelope signal through a sourcing/sinkingprocess. The switching converter 252 may output a switching currentwhich is a DC.

The ET technology using the ET modulator 250 may reduce the currentconsumption of the wireless communication system 200, and details of theET technology and the configuration of the ET modulator 250 will bedescribed in more detail with reference to FIGS. 4 to 10.

The Tx module 240 is a module for amplifying and transmitting an RFsignal to an antenna. Referring to FIG. 2, the Tx module 240 may includea PA 241 that amplifies a signal input from the transceiver 230 (or theTx operator 233), a duplexer 242 that filters a Tx signal and an Rxsignal, respectively, an antenna switching module 243 that selects eachband signal, a coupler 244 that couples a transmitted Tx signal totransmit the coupled Tx signal to the transceiver 230 through an FBRxpath, a low noise amplifier (LNA) 245 that amplifies a reception signalapplied to the antenna to transmit the amplified signal to thetransceiver 230, and at least one mobile industry processor interface(MIPI) controller 246 that adjusts respective sub blocks.

The RF signal amplified by the Tx module 240 may be transmitted to anexternal device (e.g., a base station) through the antenna.

FIG. 3 is a block diagram illustrating an electronic device, accordingto an embodiment.

Referring to FIG. 3, an electronic device 300 includes a wirelesscommunication system 310 and an AP 390.

The electronic device 300 may be a portable electronic device having awireless communication function such as a smart phone or a tabletpersonal computer (PC), and may include at least some of the componentsand/or functions of the electronic device 101 of FIG. 1.

The AP 390 may be configured to control the respective components of theelectronic device 300 and/or perform communication-related operationsand data processing, and may include at least some of the componentsand/or functions of the processor 120 of FIG. 1. The AP 390 may beoperatively, electrically, and/or functionally connected to the internalcomponents of the electronic device 300, such as the modem 320, thetransceiver 330, or the network monitor 360 of the wirelesscommunication system 310.

The AP 390 may execute instructions including control commands such asvarious arithmetic and logical operations, data movement, orinput/output stored in a memory 130.

The operation and data processing functions that can be implemented inthe electronic device 300 by the AP 390 are not limited, but in thisapplication, a function for checking a network environment in real timeand optimizing power consumption and data rate consumed by the wirelesscommunication system 310 by adjusting various parameters used in thewireless communication system 310 based on the checked networkenvironment will be described.

The wireless communication system 310 may include a modem 320, atransceiver 330, a Tx module 340, an ET modulator 350, and a networkmonitor 360. The wireless communication system 310 may support at leastone of various wireless communication protocols such as fourthgeneration (4G) communication (or long term evolution (LTE)) or 5Gcommunication (or new radio (NR)).

The network monitor 360 may check the network environment while thewireless communication system 310 performs wireless communication withan external device (e.g., a base station). In a case where theelectronic device 300 is powered on, when a data transmission eventoccurs or according to a predetermined period, the AP 390 may allow thenetwork monitor 360 to check the network environment and to provide thechecked information to the AP 390 and/or other modules in the wirelesscommunication system 310 (e.g., the CFR module, the sampling ratecontrol block, the DPD block, and the ET control block). The networkmonitor 360 may check network environment information through an FBRxpath and/or an Rx path (or Rx chain). The Rx path (or Rx chain) is apath for performing processing, such as demodulation or ADC, on an RFreception signal received from the external device at an antenna, andmay check a variety of network environment information used for the RFsignal received through the Rx path (or Rx chain). The network monitor360 may be configured as an independent block, but may also be providedon the modem 320 or the AP 390.

The network environment information may include at least one of abandwidth, a resource block, a sub-carrier spacing (SCS), or amodulation code and scheme.

More specifically, the bandwidth is the bandwidth of the RF signal to betransmitted, and the wireless communication system 310 may communicatewith a base station using some bandwidths determined in the base stationand/or a CP among determined bandwidths (e.g., 20 megahertz (MHz) forlong term evaluation (LTE) and 100 MHz for NR). The network monitor 360may check the bandwidth currently used for wireless communication.

The resource block is a unit of resources allocated based on frequencyand time in orthogonal frequency-division multiplexing (OFDM), and thewireless communication system 310 may perform wireless communicationusing some resource blocks determined in the base station and/or the CP(e.g., the auxiliary processor 123 of FIG. 1) among the entire resourceblock (e.g., 12 subcarriers*7 symbols). The network monitor 360 maycheck the resource block currently used for wireless communication.

The SCS is a bandwidth spacing of used sub-carriers, and may use a fixedSCS for each network (e.g., 15 kilohertz (KHz) for LTE) or a variableSCS (e.g., 15/30/60 KHz for NR). The network monitor 360 may check theSCS currently used for wireless communication.

The modulation scheme is a scheme for modulating a signal such as QPSK,160-QAM, 64-QAM, or 256-QAM, and the wireless communication system 310may support various modulation schemes according to a wireless networksituation. The network monitor 360 may check the modulation schemecurrently used for wireless communication.

Each of the modem 320, the transceiver 330, the Tx module 340, and theET modulator 350 may include at least some components and/or functionsof the modem 220, the transceiver 230, the Tx module 240, and the ETmodulator 250, and may further include at least one component and/orfunction for controlling each function based on the network environmentinformation obtained from the network monitor 360 in addition to thecomponents and/or functions described in FIG. 2.

The wireless communication system 310 may control the ET modulator 350,adjust a sampling rate, adjust a DPD order, apply a DPD coefficient inreal time, or determine clipping of a CFR, based on the networkenvironment information obtained from the network monitor 360.

The ET modulator 350 may adjust a drive stage in the linear regulatorbased on the network environment information (e.g., a modulation scheme,a bandwidth, a resource block, or an SCS) to determine a bias and a passcurrent I_(shoot-through). This will be described later in more detailwith reference to FIGS. 4 to 10.

The sampling rate control block may remove image/harmonic signals byadjusting a sampling frequency of a multiplier in the sampling ratecontrol block and adjusting a cutoff frequency of a baseband (BB) lowpass filter (LPF) based on the network environment information, therebydetermining the sampling rate. This will be described later in moredetail with reference to FIGS. 11 to 12.

The DPD block 236 may determine an appropriate coefficient in a DPD LUTbased on the network environment information, and may perform DPD inreal time using the determined coefficient. This will be described laterin more detail with reference to FIGS. 13 to 15.

The CFR control block 231 may adjust a clipping level during CFR byadjusting an Xmax variable and a weighting coefficient (p[n]) based onthe network environment information. This will be described later inmore detail with reference to FIG. 16.

The electronic device 300 may include only some components and/orfunctions among the above-described ET modulator 350, sampling ratecontrol block, DPD block 236, or CFR control block 231.

FIG. 4 is a block diagram illustrating an ET system, according to anembodiment.

FIG. 4 shows an ET system 400 and a power amplifier 441 for implementingET in a wireless communication system 200.

In order to support a high data rate in a wireless network such as a 5GNR, the bandwidth of a corresponding signal is widened and themodulation method of the signal is complicated, so that a peak toaverage power ratio (PAPR) can be increased. Accordingly, a poweramplifier 441 of a Tx module 240 that consumes a large amount of powerin the wireless communication system is required to have high efficiencyand high linearity. The ET technology can be applied to signalsrequiring broadband and high PAPR.

Referring to FIG. 4, a digital I/Q signal is input to a transceiver 430through each channel from a modem 220 of the ET system 400, and the I/Qsignal may be input to an envelope generator 438 and an IQ modulator439.

The I/Q signal modulated by the IQ modulator 439 may be mixed with alocal oscillator (LO) signal and may be transmitted to the poweramplifier 441 of the Tx module.

The envelope generator 438 may generate an envelope signal from the I/Qsignal. The envelope signal may include maximum values of apredetermined period of the I/Q signal. The ET DSP 435 may adjust thetype of the generated envelope signal, may perform signal processingsuch as delay adjustment on the envelope signal, and then may output theobtained signal to the ET modulator 450.

The ET modulator 450 may apply the input envelope signal as an inputpower of the power amplifier 441 of the Tx module. Accordingly, thepower amplifier 441 does not use fixed voltage input power but uses anenvelope signal of an input signal (RFIN) applied to the power amplifier441 as the input power, so that power consumed by the power amplifier441 may be reduced.

FIG. 5 is a block diagram illustrating an ET modulator and a poweramplifier of a Tx module, according to an embodiment.

Referring to FIG. 5, the ET modulator 550 includes a linear regulator551 and a switching converter 552. The linear regulator 551 may linearlyamplify an envelope signal through a sourcing/sinking process. Theswitching converter 552 may output a switching current that is a DCcurrent according to a switching frequency.

The linear regulator 551 may be a low drop-out (LDO) regulator thatoperates at a high speed but has a low efficiency, or may be a switchingmode power supply (SMPS) DC-DC converter that operates at a low speedbut has a high efficiency.

The ET modulator 550 may have a hybrid structure that includes thelinear regulator 551 and the switching converter 552, and may track anenvelope signal of a wide bandwidth while amplifying the envelope signalwith high efficiency.

FIG. 6A is a block diagram illustrating an ET modulator, according to anembodiment. FIG. 6B is a diagram illustrating current waveforms in an ETmodulator 650, according to an embodiment.

Referring to FIG. 6A, the ET modulator 650 includes a hybrid structurethat includes a linear regulator 651 and a switching converter 652.

Referring to FIG. 2, an input power Vcc of a power amplifier 241 of a Txmodule 240 may be generated according to an output current I_(out) ofthe ET modulator 650, and an output current I_(out) may be outputaccording to a source current I_(source) and a I_(sink) current Link ofthe linear regulator 651 and a switch current I_(switch) of theswitching converter 652. More specifically, the switching converter 652may generate the switch current I_(switch) that is a direct current (DC)to output the generated switch current at a predetermined switchingfrequency through a coil, and the output current I_(out) may begenerated through the sourcing/sinking process of the linear regulator651.

In FIG. 6A, the linear regulator 651 may use a fixed bias. The bias ofthe linear regulator 651 may be a bias voltage input to a buffer of thelinear regulator 651.

In the sourcing/sinking process of the linear regulator 651, crossoverdistortion noise may occur as two transistors operate alternately.Referring to the graph of FIG. 6B, the crossover distortion noise mayoccur in a crossing section between a source current and a sink current.

A pass current I_(shoot-through) may be required to reduce thiscrossover distortion noise, and the magnitude of the pass currentI_(shoot-through) may be determined by the bias condition of the linearregulator 651. To reduce the crossover distortion noise, the bias may beincreased (class-A direction) to increase the pass current, but in thiscase, power efficiency may be lowered. Conversely, when the bias currentis reduced (class-B direction) in consideration of power efficiency toreduce the pass current, a problem of crossover distortion noise mayoccur. Therefore, in order to optimize the crossover distortion noiseand power efficiency, a deep class-AB bias linear regulator may be usedas the linear regulator 651.

In order to increase the operating speed of the linear regulator 651,the current consumption of the drive stage in the linear regulator 651may increase. In addition, since the crossover distortion noise of thelinear regulator 651 that performs sourcing and sinking increases alongwith an increase in the bandwidth of the signal increases, the bias ofthe linear regulator 651 should be increased to solve this problem. Atthis time, when the bias of the linear regulator 651 increases, themagnitude of the pass current also increases, so that power efficiencyof the ET modulator 650 may be lowered.

Even in the case where the linear regulator 651 is configured with afixed bias as described above, in a network environment having a lowmaximum bandwidth (e.g., 20 MHz for LTE), there is no significantproblem in tracking the envelope signal by the ET modulator 650.However, in a network environment having a high maximum bandwidth (e.g.,100 MHz for NR), the operating speed of the linear regulator 651 must beincreased and for this, the consumption current and bias (or passcurrent I_(shoot-through)) of the drive stage of the linear regulator651 are also required to be increased. In this case, when the currentconsumption is increased in consideration of the maximum bandwidth, in alow-band signal that is frequently used in a real network environment,or a partial resource block (RB) of 4G (or LTE) communication that usesonly some of allocable RBs, or an inner RB of 5G (or NR) communication,the current may be unnecessarily consumed.

In addition, in FIG. 6A, the switching converter 652 may use a fixedswitching frequency.

The switching converter 652 may generate the switch current I_(switch)with high efficiency through a switching operation using a DC-DCconverter. One important factor that determines the efficiency of theDC-DC converter is the switching frequency. When the switching frequencyincreases, a ripple decreases, but a switching loss increases, resultingin lower efficiency. Conversely, when the switching frequency decreases,the efficiency increases and the ripple increases. Therefore, it isnecessary to maintain the switching frequency optimized according to aninput envelope signal.

Even when the switching converter 652 operates at a fixed switchingfrequency as described above, in the network environment having a lowmaximum bandwidth (e.g., 20 MHz for LTE), there may be no problem in theefficiency. However, in the network environment having a high maximumbandwidth (e.g., 100 MHz for NR), a dynamic range of an envelope signalbandwidth to be amplified increases, so that the operation of theswitching converter 652 at the fixed switching frequency may havelimitations in efficiency optimization.

FIG. 7 is a block diagram illustrating an ET modulator that performsenvelope tracking according to a network environment, according to anembodiment.

FIG. 8 is a graph illustrating a bias and a pass current according to asignal bandwidth, according to an embodiment.

The ET modulator 650 of FIGS. 6A and 6B includes the linear regulator651 of the fixed bias and the switching converter 652 of the fixedswitching frequency, resulting in low efficiency. However, the ETmodulator 750 of FIG. 7 may control the operations of a linear regulator751 and a switching converter 752 in consideration of a networkenvironment, and thus higher efficiency may be obtained compared to whenthe linear regulator 651 of the fixed bias and switching converter 652of the fixed switching frequency are used.

Referring to FIG. 7, the ET modulator 750 includes the linear regulator751, the switching converter 752, and an ET control block 755.

The ET control block 755 may obtain network environment informationincluding at least one of a bandwidth, an RB, an SCS, and a modulationscheme from a network monitor 360.

The ET control block 755 may determine the bias of the linear regulator751 and/or the switching frequency of the switching converter 752according to the input network environment information.

Referring to FIG. 8, when the bias of the linear regulator 751 isincreased (class-A direction 801) and the pass current I_(shoot-through)is increased, the operating speed of the linear regulator 751 may beincreased and accordingly envelope tracking may be implemented even in anetwork of a high bandwidth. Conversely, when the bias of the linearregulator 751 is reduced (class-B direction 802) and the pass currentI_(shoot-through) is lowered, the operating speed of the linearregulator 751 may be reduced and power consumption may be reduced.

The ET control block 755 may increase the bias of the linear regulator751 when performing communication using a high bandwidth (or at leastone of an RB, an SCS, or a modulation scheme) based on the networkenvironment information, and may reduce the bias of the linear regulator751 for the purpose of power efficiency when performing communicationwith a low bandwidth (or at least one of an RB, an SCS, or a modulationscheme).

The ET modulator 750 may include a bias control circuit that can adjustthe bias of the linear regulator 751. The ET control block 755 may driveat least a portion of the bias control circuit based on the networkenvironment information.

The ET control block 755 may store a table obtained by mapping themagnitude of the bias of the linear regulator 751 to be used and/or aportion of the bias control circuit to be driven according to thenetwork environment information (e.g., at least one of a bandwidth, anRB, an SCS, or a modulation scheme), and may perform control using thestored table.

FIG. 9 is a diagram illustrating a structure of a linear regulator of anET modulator, according to an embodiment.

FIG. 9 illustrates a case using a fixed bias to a linear regulator 950.

Referring to FIG. 9, the linear regulator 950 includes a class-AB biascircuit 951, a buffer 952, and an operational trans-conductanceamplifier (OTA) 953.

The class-AB bias circuit 951 may adjust the bias of output sourcecurrent I_(source) and sink current I_(sink) to class-AB, so that thelinear regulator 950 may operate with high efficiency through lowercrossover distortion noise.

A buffer 952 may be a final stage of the linear regulator 950, and mayoutput the source current I_(source) and the sink current I_(sink) toform an output current I_(out) together with a switching currentI_(switch) output from a switching converter 752.

The OTA 953 is an amplifier that outputs an input voltage as an outputcurrent in proportion to trans-conductance, and may amplify an appliedenvelope signal and an output envelope signal in a differential manner.The linear regulator 950 of FIG. 9 may use a fixed current to theclass-AB bias circuit 951 through a fixed current mirror. Accordingly,in the class-AB bias circuit 951, a common drain transistor may have thesame gate to source voltage (VGS) regardless of the bandwidth of an RFtransmission signal, so that the linear regulator 950 may output thesource current I_(source) and the sink current I_(sink) according to thefixed bias.

FIG. 10 is a diagram illustrating a structure of a linear regulator ofan ET modulator that performs ET according to a network environment,according to an embodiment.

FIG. 10 shows a case using a variable bias to a linear regulator 1050.

Referring to FIG. 10, the linear regulator 1050 includes a bias controlcircuit 1055 for variably controlling a bias. The bias control circuit1055 may include a plurality of transistors connected in parallel toeach other to be independently switchable.

An ET control block 755 of an ET modulator 750 may obtain networkenvironment information (e.g., at least one of a bandwidth, an RB, anSCS, or a modulation scheme) obtained from a network monitor 360. The ETcontrol block may switch the transistor of the bias control circuit 1055or adjust the ratio of a current mirror based on the network environmentinformation.

Since a current received through a bandgap reference (BGR) circuit isconstant, the current flowing in a class-AB bias circuit 1051 may beadjusted by adjusting the ratio of the current mirror differently. Forexample, when no current is output from the bias control circuit 1055 tothe class-AB bias circuit 1051, the class-AB bias circuit 1051 maygenerate a bias by a current input from the BGR circuit, and when atleast a portion of the bias control circuit 1055 is switched and acurrent flows to the class-AB bias circuit 1051, the class-AB biascircuit 1051 may generate a higher bias.

The ET control block may control the ratio of the current mirror of thebias control circuit 1055, may accordingly adjust a VGS value of acommon drain transistor, and may adjust the bias of the buffer 1052 thatgenerates the source current I_(source) and the sink current Link.Accordingly, the magnitude of the pass current I_(shoot-through) may bedetermined.

For example, when the bias control circuit 1055 includes at least oneswitch (e.g., four switches), a thermal code including binary codescorresponding to on/off of each switch may be output. The ET controlblock may output “0000” as the thermal code when a bandwidth currentlyused for an RF transmission signal is 20 MHz, and thus the bias controlcircuit 1055 does not output a current to the class-AB bias circuit1051, and the bias may be determined by the output current of the BGRcircuit. However, when the bandwidth used for the RF transmission signalincreases to a higher value, such as 40 MHz, 60 MHz, 80 MHz, or 100 MHz,the ET control block may respectively output “0001”, “0011”, “0111”, or“1111” as the thermal code to the bias control circuit 1055. Thetransistor of the bias control circuit 1055 may be switched and may beinput to the class-AB as in the current of the BGR circuit, andaccordingly, a higher bias may be generated in the linear regulator1050.

A switching converter 752 that generates a DC current of the ETmodulator with high efficiency may also adjust a switching frequency fordetermining the efficiency of a DC-DC converter based on the networkenvironment information (e.g., the bandwidth of the RF transmissionsignal).

The switching converter may include the same circuit as the bias controlcircuit 1055 of the linear regulator 1050 of FIG. 10, and the circuitmay be controlled according to the control signal of the ET controlblock. Accordingly, a switching frequency of a drive stage of theswitching converter (e.g., a drive stage 752 a in FIG. 7) may beadjusted according to the control signal of the ET control block.

FIG. 11 is a block diagram illustrating a modem and a transceiver forsampling rate control, according to an embodiment.

Referring to FIG. 11, a wireless communication system 1100 includes amodem 1120 and a transceiver 1130.

An AP 390 may process data to be transmitted to an external device as adigital signal, and an RF signal transmitted through an antenna is ananalog signal. Accordingly, the wireless communication system 1100 mayperform conversion between digital and analog signals through a DAC/ADCblock 1132.

In order to convert the analog signal into the digital signal, sampling,quantization, and coding processes are required. In the samplingprocess, a sampling rate f_(s) should be at least twice the bandwidth ofa transmission/reception baseband channel according to the Nyquisttheory. Here, an interval T_(d) between sampling points is inverselyproportional to the sampling rate f_(s). Therefore, as the sampling ratef_(s) increases, the interval T_(d) between sampling points decreases,thus the corresponding signal can be finely modulated and demodulated,and the signal can be adjusted in a shorter time unit. However, when aclock speed is increased to increase the sampling rate, an increase incurrent consumption causing heat generation and battery consumption mayoccur.

A high-performance operation through the increase in the clock speed mayhave a more important effect in a broadband ET operation. For example,when a sampling rate used in a low-bandwidth wireless communication(e.g. LTE) is used for a broadband wireless communication (e.g. NR),there is a limitation in the delay adjustment between the RF signal andthe envelope signal in the ET system, so that characteristics such asoutput power, efficiency, or linearity may deteriorate. On the otherhand, the use of a high sampling rate for broadband wirelesscommunication may cause a waste of current consumption when alow-bandwidth signal is transmitted.

Accordingly, the electronic device may determine the sampling rateoptimized for communication quality and current consumption based on thenetwork environment information.

Referring to FIG. 11, the wireless communication system 1100 includes asampling rate control block 1138 for determining a sampling rateaccording to the network environment information. The sampling ratecontrol block 1138 may include a clock generator 1138 a that generates aclock signal of a specific frequency and a multiplier 1138 b thatdetermines a coefficient to be multiplied by the clock signal todetermine the sampling rate.

The network monitor 1190 may acquire network environment informationincluding at least one of a bandwidth, an RB, or an SCS, and may providethe acquired information to the sampling rate control block 1138.

The sampling rate control block 1138 may use the network environmentinformation received from the network monitor 1190 to select anoptimized coefficient according to the current bandwidth, RB, or SCSthrough modeling and/or an algorithm of the multiplier 1138 b.Accordingly, the sampling rate of the DAC/ADC block 1132 may be adjustedby multiplying the clock signal generated by the clock generator 1138 aby the coefficient selected according to the bandwidth, the RB, or theSCS.

When the sampling rate is changed, a BB LPF 1133 a of the Tx operator1133 that rejects an image signal or a harmonic signal may also need tobe changed. The sampling rate control block 1138 may adjust a cutofffrequency of the BB LPF 1133 a in response to the sampling rate adjustedaccording to the bandwidth, the RB, or the SCS.

FIG. 12A is a diagram illustrating a method of determining a samplingrate, according to an embodiment. FIG. 12B is a diagram illustrating amethod of determining a sampling rate, according to an embodiment. FIG.12C is a diagram illustrating a method of determining a sampling rate,according to an embodiment.

FIG. 12A relates to an embodiment of determining a sampling rate onlybased on a bandwidth.

Referring to FIG. 12A, a sampling rate of 30.72 megabits per second(Mbps) in a 10 MHz bandwidth, a sampling rate of 61.44 Mbps in a 20 MHzbandwidth, and a sampling rate of 307.2 Mbps in a 100 MHz bandwidth maybe operated. In this case, since only the bandwidth is considered, thesame sampling rate may be operated when only one RB is used in thebandwidth of 10 MHz and when a full RB is used in the same. This may beinefficient because the corresponding operation is performed at the samesampling rate even though the bandwidths required for actualcommunication are different according to the number of RBs despite thesame bandwidth.

FIG. 12B relates to an embodiment of determining a sampling rate basedon the resource block.

Referring to FIG. 12B, as to the bandwidth of 100 MHz, when the RB isone RB, a sampling rate of 1.2288 Mbps may be operated, when theresource block is a half RB, a sampling rate of 153.6 Mbps may beoperated, and when the resource block is a full RB, a sampling rate of307.2 Mbps may be operated. Accordingly, even when communication isperformed in a network having the same bandwidth, the correspondingoperation is performed at a lower sampling rate depending on the numberof used RBs, thereby reducing power consumption.

FIG. 12C relates to an embodiment of determining a sampling rate basedon an SCS, according to an embodiment.

The wireless communication system may use a variable SCS (e.g., 15/30/60KHz for NR), and accordingly, the bandwidth of one RB may also bevariable. The sampling rate control block may determine the samplingrate according to the used SCS.

Referring to FIG. 12C, when the SCS used at the bandwidth of 100 MHz is15 KHz, a sampling rate of 0.6144 Mbps may be operated, when the SCS is30 KHz, a sampling rate of 1.2288 Mbps may be operated, and when the SCSis 60 KHz, a sampling rate of 2.4576 Mbps may be operated.

FIG. 13A is a graph illustrating a gain of a power amplifier and anenvelope trajectory of an ET system, according to an embodiment. FIG.13B is a diagram illustrating a method of applying DPD, according to anembodiment.

When an ET technology is applied, a power amplifier 241 may be operatedat a saturation area to optimize the overall efficiency of a system(e.g., the wireless communication system 200 of FIG. 2). When the poweramplifier 1341 follows an envelope signal of an RF signal in real timeand operates in the saturation area, Vcc may be lowered due to thecharacteristic of the power amplifier and a gain may decrease, therebyobtaining a compression characteristic as shown in FIG. 13A. Thewireless communication system may use DPD to compensate for the gaincompression characteristic.

The DPD is a method of pre-distorting an RF input signal applied to thepower amplifier by reflecting the gain characteristic of the poweramplifier according to the voltage at the common collector (Vcc) basedon an envelope trajectory that is actually used. For example, as shownin FIG. 13B, since the power amplifier has a gain characteristic 1391 inthe form of a logarithmic function as shown in FIG. 13B, a DPD block1336 may distort the RF signal in the form of an exponential function1392 and may input the distorted RF signal to the power amplifier.Accordingly, a signal 1393 amplified by the power amplifier 1341 mayhave linearity.

FIG. 14A is a diagram illustrating a method of applying DPD, accordingto an embodiment. FIG. 14B is a diagram illustrating a method ofapplying DPD, according to an embodiment.

The wireless communication system may include a DPD block thatpre-compensates for an input signal output from the modem according tothe gain compression of the power amplifier. The DPD block may store aDPD LUT capable of compensating for the gain compression. The DPD LUTmay be embedded in the DPD block at the time of manufacturing anelectronic device (or a wireless communication system).

FIG. 14A shows a case using the same DPD LUT for electronic devices A,B, and C. At this time, even if the electronic devices A, B, and C usethe same structure and components, there may be variations in thecharacteristics of the Tx path between the components. Accordingly,gains for the input power of the power amplifier may be different. InFIG. 14A, the same DPD LUT for electronic devices A, B, and C is used,and thus in some electronic devices, linearity of an output signal byDPD may not be completely compensated.

FIG. 14B shows a case using different DPD LUTs according to thecharacteristics of the electronic devices A, B, and C. For example, atthe time of manufacturing an electronic device, the DPD may bedetermined by modeling the gain characteristic of the power amplifierfor each model. In this case, since the DPD LUT modeled for each of theelectronic devices A, B, and C is used as shown in FIG. 14B, thelinearity of the output signal may be higher than the case of FIG. 14A.

However, even in the case of FIG. 14B, the determining the DPD for eachmodel of the electronic device may be performed once during calibrationin the process and the determined DPD LUT may be embedded in theelectronic device of the same model, so that applying an optimized DPDLUT for each various network scenario may be difficult. In addition,linearity may not be obtained by reflecting a change in the Txcharacteristic according to the use of the electronic device, and it maybe difficult to apply the DPD by determining the DPD LUT in real time byadapting to various RF signals transmitted in different networkenvironments.

FIG. 15 is a block diagram illustrating a wireless communication systemthat applies DPD according to a network environment, according to anembodiment.

A wireless communication system 1500 may include a DPD block 1536 thatprocesses a DPD for an RF signal to be transmitted based on networkenvironment information obtained in real time from a network monitor1560. The DPD block 1536 may be provided on a transceiver 1530 and mayperform DPD before a signal output from a modem 1520 is input to a poweramplifier 1541 of a Tx module 1540. For example, the DPD block 1536 maycause a signal which is pre-distorted with respect to a CFR-processedsignal in a CFR block 1531 to be input to a DAC/ADC block 1532.

The DPD block 1536 may store a DPD LUT that maps a DPD coefficient to beused to correspond to each network environment (e.g., at least one of abandwidth, an RB, an SCS, or a modulation scheme).

The network monitor 1560 may check the network environment throughoperations such as transit antenna selection (TAS) and/or soundingreference signal (SRS) via a Tx operator 1533 and an Rx operator 1534,and may provide network environment information 1591 related to an RFtransmission signal to the DPD block 1536. Also, the DPD block 1536 mayfurther acquire characteristic information 1592 of the Tx path throughan FBRx path.

The DPD block 1536 may generate an optimized DPD coefficient based onthe network environment information 1591 obtained through the networkmonitor 1560 and characteristic information 1592 of the Tx path obtainedthrough the FBRx path, and may pre-distort the RF transmission signal inreal time.

The wireless communication system 1500 may adjust a DPD order accordingto the network environment, and may update the DPD coefficient in realtime, thereby optimizing the performance of the wireless communicationsystem 1500 such as Tx output power, efficiency, error vector magnitude(EVM), or linearity.

A process of performing DPD using the network environment information bythe DPD block 1536 may be based on Equations (1) to (3), below.

a _(n) =f(Tx chain)  Equation (1)

In Equation (1), a_(n) may denote a DPD coefficient, and a Tx chain maydenote gain compression from the transceiver 1530 to an antenna port ofthe Tx module 1540.

X(t)′=f(X(t))=a ₀ +a ₁ X(t)+a ₂ X(t)² +a ₃ X(t)³ . . . +a _(n)X(t)^(n)  Equation (2)

In Equation (2), X(t) may denote an input RF transmission signal, andX(t)′ may denote a pre-distorted RF transmission signal.

a _(n) =f(Tx chain,BW,RB,MCS,SCS)  Equation (3)

In Equation (3), BW may denote a bandwidth of an RF transmission signalbeing used, RB may denote a resource block allocated to the RFtransmission signal, MCS may denote a modulation coding scheme, and SCSmay denote a sub-carrier spacing.

FIG. 16 is a diagram illustrating an example of signals clipped throughCFR, according to an embodiment.

A transceiver 1530 of a wireless communication system 1500 may use a CFRblock 1531 to process CFR of a transmission signal.

A CFR technology is a technology that is used to reduce a PAPR of atransmission signal so that a power amplifier 1541 of a Tx module 1540that uses a large amount of power consumption in a wirelesscommunication system of an electronic device can operate with a highefficiency. The CFR technology may be implemented through variousalgorithms, and a representative algorithm will be described below amongthe various algorithms, but the operation of a CFR block 1531 describedin this application is not limited to the algorithm described below.

The CFR may be applied through performing hard clipping and applying aLPF on an input signal. Referring to FIG. 16, a portion exceeding aclipped point in the input signal may be fixed at a specific amplitude(A_(max)), and a portion lower than the clipped point may be kept in thesame manner as in the original signal. This can be applied throughEquations (4.1) and (4.2), below.

X _(clip)[n]=c[n]*X[n]  Equation (4.1)

C[n]=Xmax/|X[n]|,|X[n]|>X _(max)

1,|X[n]|>X _(max)  Equation (4.2)

In Equations (4.1) and (4.2), X[n] may denote an input signal,X_(clip)[n] may denote a clipped signal, c[n] may denote a clippingcoefficient, and X_(max) may denote a clipped point.

Referring to FIG. 16, a sharp edge may be generated in a clipped signalC obtained by performing hard clipping on an input signal A through aclipped point B, which may be a high frequency component of the signal.High-frequency components may cause adjacent channel power (ACP). Inorder to reduce this unwanted ACP, the clipped signal C may be passedthrough an LPF to reduce the high-frequency signal corresponding to thesharp edge, and a windowed signal D may be generated.

Here, a windowing method performs filtering with a weighting coefficientp[n] and a window function w[n] to remove the high-frequency componentof the clipped signal. The windowing method may be expressed by Equation(5), below.

c′[n]=1−p[n]*w[n]  Equation (5)

In Equation (5), p[n] may denote a weighting coefficient, and w[n] maydenote a common window function such as a Gaussian function.

As described above, main parameters to be considered in the CFRtechnology are a target PAPR, a maximum order of LPF, a pass frequency,a stoppage frequency, a pass ripple, and/or a stoppage ripple.

The required specifications for QPSK/16-QAM/64-QAM/256-QAM in an LTEsystem have been established, but the usage frequency for 64-QAM and256-QAM, which are actual high order modulation, may not be large.However, for more efficient data spectrum use and maximum datatransmission speed, various signals can be actively used, including64-QAM and 256-QAM which are high-order modulation.

An error vector magnitude (EVM) specification according to a modulationscheme of a transmission signal is exemplified in Table 1, below.

TABLE 1 Modulation Unit Average EVM Level QPSK % 17.5 16QAM % 12.5 64QAM% 8 256QAM % 3.5

A high-order modulation signal may require a high quality signal becausedemodulation is complex. Therefore, the Average EVM Level may vary fromthat which is shown in Table 1.

In the case of using the CFR technology in a wireless communicationsystem, the power amplifier may be operated with high power and/or highefficiency, but EVM characteristics may deteriorate because the originalsignal is modified. In the case of a signal using low-order modulation(e.g. QPSK or 16-QAM), CFR may be processed by hard clipping becausesome high-frequency components are allowed. However, when usinghigh-order modulation such as 256-QAM as in a 5G NR network environment,it may be difficult to apply hard clipping because a strict EVMspecification is required. In addition, when the wireless communicationsystem uniformly applies soft clipping due to the EVM specification ofthe high-order modulation signal, the PAPR cannot be sufficiently low atthe time of using the low-order modulation, so that the high output ofthe power amplifier that finally amplifies the RF transmission signalmay cause a problem of low coverage in a real network environment.

The CFR block of the wireless communication system may check amodulation scheme used for the RF transmission signal and may performCFR with a corresponding clipping level. The CFR block may determine aclipping level applied to the CFR based on the network environmentinformation. The CFR block may acquire information related to themodulation scheme currently being used for the RF transmission signal inreal time or periodically from a network monitor 1500.

Accordingly, if CFR is performed using the same clipping coefficientregardless of the modulation scheme in a conventional CFR algorithm, thewireless communication system may determine the clipping level by themodulation scheme in real time.

The CFR algorithm may be performed as shown in Equations (6) to (8),below.

X _(max)′[n]=f(MCS)  Equation (6)

In Equation (6), X_(max)′ [n] may be a clipped point determined inconsideration of the modulation scheme, which can be calculated as afunction of a modulation coding scheme (MCS).

c′[n]=1−p[n]*w[n]  Equation (7)

In Equation (7), p[n] may denote a weighting coefficient, and w[n] maydenote a common window function such as a Gaussian function.

p[n]=f(MCS)  Equation (8)

In Equation (8), the weighting coefficient p[n] can be calculated as afunction of MCS.

FIG. 17 is a block diagram illustrating a wireless communication system1700 that controls various parameters according to a networkenvironment, according to an embodiment.

FIG. 17 may include the components of the wireless communication system200 of FIG. 2, and may acquire, when compared to FIG. 2, networkenvironment information using a network monitor 1760 and may perform atleast one of, for example, controlling the ET modulator 1750, adjustinga sampling rate, adjusting a DPD order and applying a DPD coefficient inreal time, or determining clipping of CFR based on the acquired networkenvironment information.

Hereinafter, in order to avoid redundant descriptions, the technicalfeatures described with reference to FIGS. 1 to 16 will be omitted.

Referring to FIG. 17, the network monitor 1760 may check a networkenvironment while a wireless communication system performs wirelesscommunication with an external device (e.g., a base station). When theelectronic device is turned on or according to a predetermined period,an AP may allow the network monitor 1760 to check the networkenvironment and to provide the checked information to the AP and/or thewireless communication system (e.g., the CFR block 1731, the DPD block1736, the sampling rate control block 1739 and the ET control block1759). The network monitor 1760 may check the network environmentinformation through an FBRx path and/or an Rx chain. The network monitor1760 may be configured as an independent block, but may be provided onthe modem 1720 or the AP 390.

The network environment information may include at least one of abandwidth, an RB, an SCS, or a modulation scheme.

The ET control block 1759 may adjust a drive stage in the linearregulator 1751 of the ET modulator 1750 based on the network environmentinformation to determine a bias and a pass current I_(shoot-through). Amethod of controlling the drive stage of the linear regulator 1751and/or the switching converter 1752 by the ET control block 1759 basedon the network environment information and the circuit configurationtherefor have been previously described with reference to FIGS. 9 to 10.

The sampling rate control block 1739 may determine a sampling rateaccording to the network environment information. The sampling ratecontrol block 1739 may receive at least one piece of information relatedto the current bandwidth, RB, or SCS from the network monitor 1760, andmay determine the sampling rate to be used for sampling an RFtransmission signal.

The sampling rate control block 1739 may select a coefficient optimizedaccording to the at least one of the current bandwidth, RB, or SCSthrough modeling and/or an algorithm of the multiplier. Accordingly, thesampling rate of the DAC/ADC may be adjusted by multiplying a clocksignal generated by the clock generator by the coefficient selectedaccording to the bandwidth, the RB, or the SCS. The method ofcontrolling the sampling rate based on the network environmentinformation by the sampling rate control block 1739 and the circuitconfiguration therefor have been previously described with reference toFIGS. 11 to 12.

The DPD block 1736 may process a DPD for an RF signal to be transmittedbased on the network environment information acquired in real time. TheDPD block 1736 may be provided on the transceiver 1730, and may performDPD before a signal output from the modem 1720 is input to the poweramplifier 1741 of the Tx module 1740. The DPD block 1736 may store a DPDLUT mapping a DPD coefficient to be used in correspondence with eachnetwork environment (e.g., at least one of the bandwidth, the RB, theSCS, or the modulation scheme). The method of performing DPD based onthe network environment information by the DPD block 1736 and thecircuit configuration therefor have been previously described withreference to FIGS. 13 to 15.

The CFR block 1731 may check the modulation scheme used for the RFtransmission signal based on the network environment informationreceived from the network monitor 1760, and may perform CFR with acorresponding clipping level. A method of performing CFR based on themodulation scheme by the DPD block 1736 has been previously describedwith reference to FIG. 16.

Various embodiments of the application may include at least some of thecomponents of FIG. 17. For example, the electronic device may include atleast some of the CFR block 1173, the DPD block 1736, the sampling ratecontrol block 1739, and the ET control block 1759, which performdetermined processing by adapting to the network environment.Alternatively, some of the blocks may operate using fixed parameterswithout using the network environment information.

According to an embodiment, an electronic device may include a networkmonitor configured to acquire network environment information related toan RF transmission signal; a transceiver configured to generate anenvelope signal of the RF transmission signal; a Tx module including apower amplifier for receiving the RF transmission signal from thetransceiver and amplifying the RF transmission signal; and an ETmodulator configured to receive the envelope signal from the transceiverand to provide a bias of the power amplifier to correspond to theenvelope signal, wherein the ET modulator may determine a magnitude ofthe bias of the power amplifier based on the network environmentinformation acquired by the network monitor.

The ET modulator may include a linear regulator configured to linearlyamplify the envelope signal and the switching converter configured tooutput a switching current according to a switching frequency, and theET modulator may output an output current to the Tx module, wherein theoutput current is obtained by mixing a pass current output from thelinear regulator with the switching current.

The ET modulator may further include an ET control block configured todetermine a magnitude of the pass current output from the linearregulator based on the network environment information.

The ET control block may control the magnitude of the pass current to beincreased when the RF transmission signal is a high-bandwidth signalbased on the network environment information.

The liner regulator may include a bias control circuit configured toinclude a plurality of transistors that can be switched according to acontrol signal of the ET control block, and the ET control block maycontrol a magnitude of a current that is input as a bias of the linearregulator from the bias control circuit based on the network environmentinformation.

The ET control block may determine the switching frequency of theswitching converter based on the network environment information.

The electronic device may further include a DAC configured to convert adigital signal into an analog signal and the sampling rate control blockconfigured to determine a sampling rate of the DAC based on the networkenvironment information.

The sampling rate control block may determine the sampling rate bymultiplying a clock signal generated by the clock generator with acoefficient selected according to the network environment information.

The electronic device may further include the DPD block configured tooutput a linearized signal by pre-distorting the RF transmission signalaccording to a gain characteristic of the power amplifier, and the DPDblock may distort the RF transmission signal using a DPD coefficientcorresponding to the network environment information.

The electronic device may further include the CFR block configured toreduce a PAPR of the RF transmission signal by clipping at least aportion of the RF transmission signal, and the CFR block may determine aclipping level for applying the CFR based on the network environmentinformation.

The network environment information may include at least one of abandwidth, an RB, an SCS, or a modulation scheme.

The network monitor may acquire the network environment informationrelated to the RF transmission signal through at least one of an FBRxpath and an Rx path.

The network monitor may acquire the network environment information whenthe electronic device is powered on or for each predetermined period.

The electronic device may further include the modem configured totransmit a digital baseband signal to the transceiver, and the networkmonitor 1760 may be included in the modem.

The electronic device may output the RF transmission signal according toa 5G NR communication scheme.

FIG. 18 is a flowchart illustrating a method of operating a wirelesscommunication system, according to an embodiment.

The illustrated method may be performed by the electronic device (or thewireless communication system) described with reference to FIGS. 1 to 17above, and the description of the technical features described abovewill be omitted below.

In step 1811, an electronic device 300 is powered on. After theelectronic device 300 is powered on in step 1811, the electronic devicemonitors network environment information using a network monitor 360 instep 1821.

The network monitor 360 may monitor the network environment informationin step 1821 by performing Tx chain calibration in step 1823 and/or byperforming Rx chain calibration in step 1822. The network environmentinformation may include at least one of a bandwidth detected in step1831, an RB detected in step 1832, an SCS detected in step 1833, or amodulation scheme detected in step 1834.

In step 1841, an ET control block 755 controls a drive stage of a linearregulator 751 and/or a switching converter 752 of the ET modulator 750based on at least one of the detected bandwidth, RB, or SOS information.

In step 1842, a sampling rate control block 1138 determines a samplingrate based on the at least one of the detected bandwidth, RB, or SCSinformation. For example, the sampling rate control block 1138 mayadjust a sampling frequency of a multiplier 1138 b in the sampling ratecontrol block 1138 and a cutoff frequency of a BB LBF 1133 a to removeimage/harmonic signals.

In step 1843, a DPD block 1336 receives the bandwidth, the RB, the SCSinformation and the modulation scheme information obtained from thenetwork monitor and a characteristic of a transmitted Tx signal throughthe FBRx, and determines and updates a DPD LUT in real time.

A DPD order may be embedded in a DPD LUT determination model to adjust aused order according to the type of signal. The DPD coefficient maycharacterize the Tx path based on the FBRx information detected in realtime and may determine an optimized DPD coefficient by using the DPDorder that matches the type of the signal.

In step 1844, a CFR block 1173 adjusts a clipping level by adjusting aclipping point and a weighting coefficient p[n] according to amodulation scheme of a transmitted signal.

According to an embodiment, a control method of a wireless communicationsystem of an electronic device may include acquiring network environmentinformation related to an RF transmission signal; generating an envelopesignal of the RF transmission signal; and providing a bias of a poweramplifier for amplifying the RF transmission signal to correspond to theenvelope signal, wherein providing the bias may include determining amagnitude of the bias of the power amplifier based on, the networkenvironment information.

Determining the magnitude of the bias may include at least one ofdetermining a magnitude of a pass current output from a linear regulatorfor linearly amplifying the envelope signal based on the networkenvironment information and determining a switching frequency of theswitching converter for outputting a switching current according to theswitching frequency based on the network environment information.

Determining the magnitude of the pass current may include increasing themagnitude of the pass current when the RF transmission signal is a highbandwidth-signal.

The network environment information may include at least one of abandwidth, an RB, an SCS, or a modulation scheme.

Acquiring the network environment information may include acquiring thenetwork environment information related to the RF transmission signalthrough at least one of an FBRx path and an Rx path.

While the present disclosure has been particularly shown and describedwith reference to certain embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the disclosure as defined by the appended claims and theirequivalents.

What is claimed is:
 1. An electronic device comprising: a networkmonitor configured to acquire network environment information related toa radio frequency (RF) transmission signal; a transceiver configured togenerate an envelope signal of the RF transmission signal; atransmission (Tx) module including a power amplifier for receiving theRF transmission signal from the transceiver and amplifying the RFtransmission signal; and an envelope tracking (ET) modulator configuredto receive the envelope signal from the transceiver and to provide abias of the power amplifier to correspond to the envelope signal,wherein the ET modulator determines a magnitude of the bias provided tothe power amplifier based on the network environment informationacquired by the network monitor.
 2. The electronic device of claim 1,wherein the ET modulator comprises a linear regulator configured tolinearly amplify the envelope signal and a switching converterconfigured to output a switching current according to a switchingfrequency, wherein the ET modulator outputs an output current to the Txmodule, and wherein the output current is obtained by mixing a passcurrent output from the linear regulator with the switching current. 3.The electronic device of claim 2, wherein the ET modulator furthercomprises an ET control block configured to determine a magnitude of thepass current output from the linear regulator based on the networkenvironment information.
 4. The electronic device of claim 3, whereinthe ET control block controls the magnitude of the pass current to beincreased when the RF transmission signal is a high-bandwidth signalbased on the network environment information.
 5. The electronic deviceof claim 3, wherein the linear regulator comprises a bias controlcircuit including a plurality of transistors capable of being switchedaccording to a control signal of the ET control block, and the ETcontrol block controls a magnitude of a current that is input as a biasof the linear regulator from the bias control circuit based on thenetwork environment information.
 6. The electronic device of claim 3,wherein the ET control block determines the switching frequency of theswitching converter based on the network environment information.
 7. Theelectronic device of claim 1, further comprising: a digital to analogconverter (DAC) configured to convert a digital signal into an analogsignal; and a sampling rate control block configured to determine asampling rate of the DAC based on the network environment information.8. The electronic device of claim 7, wherein the sampling rate controlblock determines the sampling rate by multiplying a clock signalgenerated by a clock generator by a coefficient selected according tothe network environment information.
 9. The electronic device of claim1, further comprising: a digital pre-distortion (DPD) block configuredto output a linearized signal by pre-distorting the RF transmissionsignal according to a gain characteristic of the power amplifier,wherein the DPD block distorts the RF transmission signal using a DPDcoefficient corresponding to the network environment information. 10.The electronic device of claim 1, further comprising: a crest factorreduction (CFR) block configured to reduce a peak to average power ratio(PAPR) of the RF transmission signal by clipping at least a portion ofthe RF transmission signal, wherein the CFR block determines a clippinglevel applied to the CFR based on the network environment information.11. The electronic device of claim 1, wherein the network environmentinformation comprises at least one of a bandwidth, a resource block, asub-carrier spacing (SCS), or a modulation scheme.
 12. The electronicdevice of claim 1, wherein the network monitor acquires the networkenvironment information related to the RF transmission signal through atleast one of a feedback (FB) reception (Rx) (FBRx) path and an Rx path.13. The electronic device of claim 1, wherein the network monitoracquires the network environment information when the electronic deviceis powered on or for each predetermined period.
 14. The electronicdevice of claim 1, further comprising: a modem configured to transmit adigital baseband signal to the transceiver, wherein the network monitoris included in the modem.
 15. The electronic device of claim 1, whereinthe electronic device outputs the RF transmission signal according to afifth generation (5G) new radio (NR) communication scheme.
 16. A controlmethod of a wireless communication system of an electronic device, thecontrol method comprising: acquiring network environment informationrelated to a radio frequency (RF) transmission signal; generating anenvelope signal of the RF transmission signal; and providing a bias of apower amplifier for amplifying the RF transmission signal to correspondto the envelope signal, wherein providing the bias comprises determininga magnitude of the bias of the power amplifier based on the networkenvironment information.
 17. The control method of claim 16, whereindetermining the magnitude of the bias comprises at least one of:determining a magnitude of a pass current output from a linear regulatorfor linearly amplifying the envelope signal based on the networkenvironment information, and determining a switching frequency of aswitching converter for outputting a switching current according to theswitching frequency based on the network environment information. 18.The control method of claim 17, wherein determining the magnitude of thepass current comprises increasing the magnitude of the pass current whenthe RF transmission signal is a high bandwidth-signal.
 19. The controlmethod of claim 16, wherein the network environment informationcomprises at least one of a bandwidth, a resource block, a sub-carrierspacing (SCS), or a modulation scheme.
 20. The control method of claim16, wherein acquiring the network environment information comprisesacquiring the network environment information related to the RFtransmission signal through at least one of an feedback (FB) reception(Rx) (FBRx) path and an Rx path.